CVE-2026-66005

MEDIUM

Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding

Title source: cna
STIX 2.1

Description

Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.

References (4)

Core 4
Core References
Exploit technical-description exploit issue-tracking
Researcher Disclosure
https://github.com/janhq/jan/issues/8453
Issue Tracking issue-tracking patch
Pull Request
https://github.com/janhq/jan/pull/8506

Scores

CVSS v3 6.3
EPSS 0.0019
EPSS Percentile 8.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-183 CWE-942
Status published
Products (2)
janhq/jan < 0.8.4
janhq/jan 3e1c1e724f696620d89bb4a9cc18a380e0753757
Published Jul 24, 2026
Tracked Since Jul 24, 2026